From 3f0580f2546de8be7acf1bc78a55a257bc638ebe Mon Sep 17 00:00:00 2001
From: Bartosz Brachaczek <b.brachaczek@gmail.com>
Date: Tue, 12 Nov 2019 14:31:08 +0100
Subject: [PATCH] Make HgfsConvertFromNtTimeNsec aware of 64-bit time_t on i386

I verified that this function behaves as expected on x86_64, i386 with
32-bit time_t, and i386 with 64-bit time_t for the following values of
ntTtime:

UNIX_EPOCH-1, UNIX_EPOCH, UNIX_EPOCH+1, UNIX_S32_MAX-1, UNIX_S32_MAX,
UNIX_S32_MAX+1, UNIX_S32_MAX*2+1

I did not verify whether the use of Div643264 is optimal, performance
wise.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
---
 lib/hgfs/hgfsUtil.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/lib/hgfs/hgfsUtil.c b/lib/hgfs/hgfsUtil.c
index cc580ab8..49b10040 100644
--- a/lib/hgfs/hgfsUtil.c
+++ b/lib/hgfs/hgfsUtil.c
@@ -110,23 +110,21 @@ HgfsConvertFromNtTimeNsec(struct timespec *unixTime, // OUT: Time in UNIX format
 			  uint64 ntTime) // IN: Time in Windows NT format
 {
 #ifdef __i386__
-   uint32 sec;
-   uint32 nsec;
+   uint64 sec64;
+   uint32 sec32, nsec;
+#endif
 
    ASSERT(unixTime);
-   /* We assume that time_t is 32bit */
-   ASSERT_ON_COMPILE(sizeof (unixTime->tv_sec) == 4);
 
-   /* Cap NT time values that are outside of Unix time's range */
+   if (sizeof (unixTime->tv_sec) == 4) {
+      /* Cap NT time values that are outside of Unix time's range */
 
-   if (ntTime >= UNIX_S32_MAX) {
-      unixTime->tv_sec = 0x7FFFFFFF;
-      unixTime->tv_nsec = 0;
-      return 1;
+      if (ntTime >= UNIX_S32_MAX) {
+         unixTime->tv_sec = 0x7FFFFFFF;
+         unixTime->tv_nsec = 0;
+         return 1;
+      }
    }
-#else
-   ASSERT(unixTime);
-#endif
 
    if (ntTime < UNIX_EPOCH) {
       unixTime->tv_sec = 0;
@@ -135,9 +133,15 @@ HgfsConvertFromNtTimeNsec(struct timespec *unixTime, // OUT: Time in UNIX format
    }
 
 #ifdef __i386__
-   Div643232(ntTime - UNIX_EPOCH, 10000000, &sec, &nsec);
-   unixTime->tv_sec = sec;
-   unixTime->tv_nsec = nsec * 100;
+   if (sizeof (unixTime->tv_sec) == 4) {
+      Div643232(ntTime - UNIX_EPOCH, 10000000, &sec32, &nsec);
+      unixTime->tv_sec = sec32;
+      unixTime->tv_nsec = nsec * 100;
+   } else {
+      Div643264(ntTime - UNIX_EPOCH, 10000000, &sec64, &nsec);
+      unixTime->tv_sec = sec64;
+      unixTime->tv_nsec = nsec * 100;
+   }
 #else
    unixTime->tv_sec = (ntTime - UNIX_EPOCH) / 10000000;
    unixTime->tv_nsec = ((ntTime - UNIX_EPOCH) % 10000000) * 100;
-- 
2.25.1

